Vista Business Crashing

> Hi Friends,
>
> I have a small home network,
>
> Vista Laptop -----> D-Link Ethernet Router <-------- XP Home SP2
> Laptop
>
> On the XP laptop, there is a Western Digital External Hard disk, which
> I have shared through the home network.
>
> The problems I face,
>
> The network connection between the home PCs is very intermittent.. It
> works, and then it doesn't ... No idea why it stops. But once I do a
> ping -a to the xp laptop, the connections are restored.
>
> When I can access the shared drives, copying of files to and fro works
> fine.. but slow..
>
> However, When I tried to run a program (residing on shared drives),
> Vista treats me with the blue screen... a crash...
>
> Please help...
>
>
> regards
> raghav..
>
>